Publications

4477

This study reports the draft genome of ‘ Candidatus Phytoplasma pyri’ strain P1, isolated from Argentina. The genome assembly consisted of 17 contigs, with a total length of 575,431 bp, a GC content of 20.35%, and 125× coverage. A total of 537 genes were annotated, including those related to metabolism, genetic information processing, and signaling. Phylogenetic analysis placed ‘ Ca. Phytoplasma pyri’ within the 16SrX group, supporting its classification as a distinct species from ‘ Ca. Phytoplasma mali’ and ‘ Ca. Phytoplasma prunorum’, with average nucleotide identity values ranging from 90.3 to 90.5%. In contrast, strain P1 shares 98.1% average nucleotide identity with the Chilean strain ‘ Ca. Phytoplasma pyri’ UCh_1, supporting their classification as members of the same species. The investigation also identified 12 secreted proteins, including homologs of known effectors, as well as conserved proteins associated with virulence mechanisms. A homolog of the immunodominant membrane protein was also characterized, revealing conserved gene organization across related strains. These findings contribute to the understanding of ‘ Ca. Phytoplasma pyri’ pathogenicity and provide valuable genomic data for future research. [Formula: see text] Copyright © 2025 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

‘ Candidatus Phytoplasma prunorum’ is associated with European stone fruit yellows disease, affecting wild and cultivated species of Prunus at different degrees of susceptibility, and so far is being mainly restricted to Europe. Here, we report draft genome sequences for ‘ Ca. Phytoplasma prunorum’ strains ESFY1 and LNS1, which represent the first available for this species. Strain ESFY1 is the causal agent of the European stone fruit yellows disease of P. persica in Germany, and LNS1 is the causal agent of leptonecrosis disease of P. salicina in Italy. Their draft genomes consist of 480,123 and 490,930 bases assembled into 28 and 16 contigs, with an average GC content of 21.1 and 20.7%, respectively. Analysis of average nucleotide identity (ANI) values between genomes further supported the delineation of ‘ Ca. P. prunorum’ as a species distinct from ‘ Ca. P. mali’, in agreement with previous phylogenetic data. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

ABSTRACT The phyllody severity in sesame crop ranged from 9% to 20% under field conditions, and the maximum was recorded in Thiruvannamalai district of Tamil Nadu, India. The observed morphological characters of the transmitting insect vector Orosius albicinctus were light ochraceous colour with irregular striations and dark brown with black mottling. The infected sesame samples were subjected to PCR amplification by using universal primer pair P1/P6, followed by nested PCR using R16F2n/R16R2 primers, which amplified ~1.25 kb, which was also occurred in the Parthenium weed plant. Further, BLAST analysis showed that the sequences were aligned with the 16SrII‐B group phytoplasma consisting of Candidatus Phytoplasma aurantifolia (94.87%), sesame phyllody (97.97%), Blainvillea acmella phytoplasma (97.70%) and Mollugo disticha phyllody phytoplasma (98.28%). Since there is no adorus impact despite the vast host range, polyphagous insect vectors, lack of environmentally acceptable effective insecticide, and unavailability of resistant sources, management of phyllody disease has been attempted with biotic inducers (salicylic acid [SA], methyl jasmonate [MeJA] and beta amino butyric acid [BABA]) individually (50, 100 and 150 ppm) and in combination. Among the inducers tested in vitro, SA 50 ppm showed a higher vigour index (1401) in the seed infiltration method of seed treatment, further confirmed in blotter paper technique. The same treatment showed a high germination percentage (86%) with more shoot length on the 60th day (67.0 cm) and five branches/plant under glasshouse experiment. In addition, SA 50/100 ppm increased the phenolic activity and plant defence enzymes; hence it has been further test verified at two different field locations, and the results revealed that seed infiltration treatment with SA 50/100 ppm, followed by foliar application of SA (50/100 ppm) at 30, 45 and 60 DAS, was shown to be effective by recording lesser disease severity compared to control (42.2%). Also, salicylic acid treatment showed higher germination (87.6%), more capsules/plant, thereby incorporation of inducers like salicylic acid in the integrated disease management will serve as a viable and sustainable management option.

Methanotrophic bacteria in peatlands mitigate emissions of methane (CH4), a potent greenhouse gas. Yet, the identity, physiology, and adaptive traits of methanotrophs inhabiting acidic peatlands are still not fully characterised. Using classical enrichment methods and single-cell sorting, we isolated a novel bacterial methanotroph species from Czech peatland soil: 'Candidatus Methylocystis sumavensis'. 'Ca. M. sumavensis' is moderately acidotolerant, growing optimally at pH 6.8 and 24 – 37°C, with a CH4 oxidation rate of 14.2 ± 0.51 nmol CH4 µg protein-1 · hr-1. The complete genome encodes two isozymes of particulate methane monooxygenase and genes providing the capacity for nitrous oxide reduction to di-nitrogen (N2O). This suggests a potential role as a N2O sink, possibly enabling the new species to oxidise CH4 under low-oxygen or anoxic conditions. The presence of four terminal oxidases, two of which are of a high-affinity type, and two different [NiFe]-hydrogenases (3b and a putative 4f group) suggests a capacity for diverse respiratory processes, likely including anaerobic metabolism. Several acid stress response systems, most strikingly a H+/Na+-translocating F-type ATP synthase in addition to a classical H+-translocating F-type ATP synthase, likely support survival in the isolates’ oligotrophic, acidic habitat. Our results reveal that the new methanotroph species combines unique metabolic traits, reflecting its adaptation to peat ecosystems and indicating a possible broader ecological role for peat-inhabiting methanotrophs beyond aerobic CH4 oxidation.